Directional well bore roller bit



C. J.. CARR EI'AL lDIRECTIONAL WELL BORE RLIJTR BIT May 12, v1959 FiledJan. 1o, 1955 35 INVENTUM, vi1/maf: .Z klee .J2/w55 Wr/Mae# May 12, 1959C'. .1. CARR Erm. 2,886,293

' DIRECTIONAL WELL BoRE ROLLER BIT Y 2 sheets-sheet 42 22. me? Si 77 847a a4 @5f INVENToRs,

ras/vr vnr United States Patent C DIRECTIONAL WELL BoRE ROLLER BITCharles J. Carr, Long Beach, and James B. Washburn, Lomita, Calif.

Application January 10, 1955, Serial No. 480,830

' s Claims. (ci. zss-sls) This invention has to do with a well drillingbit and it is a general object of the present invention to provide awell tool construction wherein the active parts or cutters of the toolare particularly adapted for use in directionally cutting a well bore toa specified gauge.

Thisapplication is iiled as a continuation-in-part of our now abandoned,application Serial No. 428,336 entitled, .Bore Reaming Roller Bit, ledMay 7, 1954.

It is a primary objectof this invention to provide a well boring rollerbit which acts to eiectively penetrate the earth formation and whichacts to gauge the well bore at the bottom thereof. In the tool of thepresent invention there are cutters which simultaneously act upon theside wall of the well bore as well as upon the bottom thereof.

An object of this invention is to provide a cutter construction for awell drilling tool of the character referred to, which has cuttingaction on the bottom and the sides of the lower end portion of the wellbore so that the operator by controlling the drilling string candetermine the angle of drilling. The tool of the present invention issensitive to weight so that the operator by increasing the weight of thedrilling string upon the tool can build up angle in a well bore, or bydecreasing the weight of the drilling string can allow the tool to drilldownwardly or to drop angle. By employing the tool of the presentinvention a Well bore may be maintained at a given deection after awhipstocking operation without deviating from side to side.

It is also an object of this invention to provide a bore reaming rollerbit having both bottom cutters that dig the bore and side reamingcutters that gauge the bore, and

which bit is characterized by the absence of outside leg constructionsso that the body of the tool does not come into contact with the wellbore.

It is another object of the invention to provide ushing means for thecutters of a bore reaming roller bit of the character referred to, whichmeans acts to clean both the periphery and the outside cutting faces ofthe roller cutters.

It is still another object of this invention to provide a bore reamingroller bit which acts to open a well bore to full bit diameter and inwhich the cutters of the bit are of maximum size and are so related tothe elements of the structure lthat maximum chip clearance is provided.

Thefvarious objects and features of our invention will be fullyunderstood from the following detailed description of typical preferredforms and applications of our invention, throughout which descriptionreference is made to the accompanying drawings, in which:

Figs. l and 2 are cross sectional views taken through a well bore,showing the mode of operation of the roller bit provided by theinvention. Fig. 1 shows the bit in operation vto maintain a given angleof deection, while Fig. 2. shows the bit in operation to build angle orto increase the amount of deection. Fig. 3 is an enlarged detailedsectional view`of-the bit that we provide and Mice taken as indicated byline 3-3 on Fig. 5. Fig. 4 is a view taken as indicated by line 4-4 onFig. 3, showing the structure in cross section. Fig. 5 is an enlargedlower end view of the roller bit taken as indicatedby line 5--5' on Fig.3 and Fig. 6 is an end view of one of the cutters taken as indicated byline 6-6 on Fig. 3.

The bit T of the present invention is adapted for use at the lower endof a drilling string S which may involve a drill collar 10, a stabilizer11 and a sub 12. The stabilizer 11 is inserted between the drill collar10 and sub 12, and the bit T is carried at the lowermost end of thedrill string S by the bottom portion of the sub` 12 which is internallythreaded at 13 to receive the bit T.

The bore reaming roller bit T provided by this invention acts upon thecylindrical side wall 14'of the bore as well as upon the bottom end 15thereof and involves, generally, a body A, a pin B projecting upwardlyfrom the body, substantially disc-shaped bore gauging cutters C carriedat the sides of the bodyA, roller-type bottom or cross sectional cuttersD carried at the bottom of thel body A, anti-friction means rotatablycarrying the cutters C, anti-friction means rotatably carrying thecutters D, and flushing means E for cleaning the cutters C and D.

The body A is an elongate vertically disposed element having an outerwall 16, a top face 17 and a depending cutter carrying portion 18. Theouter wall 16 is preferably of the same diameter as the drill string'Sand extends downwardly from the lower end of the drill string S. The topface 17 faces upwardly and has seating engagement with a lower end face18' at the bottom end of the sub 12.

The depending cutter carrying portion 18 'of the body A is characterizedby and involves a pair of legs 19 and 20 that extend downwardly fromopposite sides of the body, a web 21 that extends between and joins thelegs, and a pair of arms 22 and 23 that also extend downwardly fromopposite sides of the body. The parts of the body A are preferablyformed of a single body of material and the legs 19 and 20 projectdownwardly in substantially diverging planes which are positioned sothat the projecting intersecting apex of the planes extend through thevertical axis of the body A while the arms 22 and 23 projectingdownwardly in parallel planes spaced radially of the vertical axis ofthe body and at right angles to the planes in which the legs occur. Theweb 21 extends between the legs 19 and 20 at or near the vertical axisof the structure thereby tying the legs together to prevent spreadingand distortion thereof.` The arms 22 and 23 are also spaced and dependfrom diametrically opposite sides of the body A. v

The bore gauging cutters C are substantiallyy discshaped members and areon axes which extend trans-- versely of the body A, and are normal tothe planes ina which the legs occur. The roller type cutters D are on amaxis substantially normal to the axes of the cutters CI and intersectthe axes of the arms 22 and 23 and the vertical axis of the body so thatthe axes of the cutters C and D are normal to each other in plan view,as illustrated in Fig. 5 of the drawings.

The pin B is in the form of a tapered screw threaded part that projectsupwardly from the rface 17 of the body A and has a threaded exterior 24and a central uid handling bore 25. The exterior 24 is screw threadedinto the bottom of the sub 12 at 13, and the bore 25 terminates at abottom 26 at or within the upper end of the body A.

The bore gauging cutters C are alike and are provided to act upon thecylindrical wall 14 of the well bore as well as upon the peripheralportion of the bottom 15 thereof. Each cutter C is a wheelor disc-shapedelement 30 having a side cutting end'portion 31 and a bottom cuttingperipheral portion 32. The element 30 has inner'and outer-peripheralcorner edges 33 and 34, and as shown"throughoutvth@drawings; the cuttingend vportion 31 has a frusto-conical-face that is confined within theouter peripheral edge 34`of the element 30. The portions 31?: and 32-offthe cutterse() are formedconcentric with* the central axisofthecutters Thelcutters" C act upon= the` outer portion` of the Wellbore'andtrirn or rearnI the- Wellbore to gauge -asthe earth formation ispenetrated; Each cutterC'is-carriedon anY inclinedaxis that extendsv`upwardly and outwardlyl from the' body' portion18-andthe centrallongitudinal axis of theA-tool, so that the-fface'othe side cutting endportion offth'e e1ement'30 liesadjacentto the side 14 vof the'wellboreand so that the-bottomcutting*peripheral portion tl1`e-well bore.Inl theV preferredY form of the invention the portions 31 andA 32of theelementlti areso related that 'the frustof-conical cuttingv face ofportion 31 conformsto the circular sideV 14 of the well bore, whilethedownwardly disposed tapered portionl 32 is substantially parallel tothebottom 15 of the well bore.

An annularseries of teeth 35 extend aroundthe circumference of theperipheral portion 32.of the element f'toproject radially-outwardlytherefrom. The teeth SSV-may bev-shaped with cutting edges and arepreferablyhelically formed and extend between the edges 33 and'34-oflthe element 30. In practice, suitable hardfacing-37 is applied tothe-cuttingfedges as is common practice in tools of the type underconsideration. The teeth35 may be equally spaced circumferentially ofthe cutteror'they may be unequally spaced or staggered, as circumstancesrequire.

The Vside cutting portion- 31 ofeach bore gauging cutter Chas asubstantially radially disposed, longitudinally outwardly inclined face33 concentric with the axis of the'cutter. Theface 38 isl coextensivewith the outer end offthevr cutter C, and terminates at the outerperipheral edge34thereof. In accordance with the present inven tion,-an7 annular series of borel gauging teeth 39 project axially outwardlyfronrtheface` 38 Vofeach cutter C. As clearlyy illustrated in Figs. 3and 6 of the drawings, the teeth-V 39 are in the form of ridges that`extend radially from the central portionof the cutter to the outerperipl eral portion thereof. In practice, each tooth 39 is in radialalignmentwith one of the teeth 13S-'and is extended radially outwardlyto overlie the adjacent end of the tooth 35 Arelated thereto.

Since thefcutters C are establishedv frorn a'single piece of stockandare formed by a forging and/ or machining operation, itwill beapparentthat the adjacent or related teeth- 35and 39 thereof are in factintegrally joined together.

It is preferred that there be a tooth 39 for every other tooth 35, asshown.`

Each ridge-like'tooth 39 has an outer land 40 extendingflongitudinallyvthereof, whichY land is spherically formedfrom a center coincident withthey vertical axis of the-bit. In'the-caseA illustratedthe inner end ofthe land 40of each tooth 39 terminates at a point spaced from thecentral axis ofthe cutter, while its outerend terminatos-at the' cuttingedge'36 of the toothV 3-5 related thereto.-

When the bit of the present invention is operated to penetrate earthformation it is rotated in aclockwise direction as indicated throughoutthe drawings, in which case the tcutter C revolvesY in acounter-clockwise direction relative to the body A. The teethA 39 aretherefore successively brought into cutting engagement'vvith the earthformation. Eachtooth 39 has a'leading cutting edge 42 and a trailingcutting edge 43. which are coextensivey With-the'tooth atthe sidesyofthe land 4l) so that the :teeth are effective in removing'earthformation from the side-14 ofthe well bore; Suitable hard-facing maybevapplied to. the teeth" 39 as circumstances require. Notches- 457-1arevprovided in the teeth 39v to allow for 4E chip clearance and ineffect establish concentric inner and outer annular serieseof-teethw Thebottom or cross sectional cutters D are substantially alike, and areprovided to act upon the bottom of the well bore and are characterizedby cylindricallyshaped elements 50 and 50. The elements 50 and 50' arepreferably inwardly tapered and have annular sets or series of teeth 52and 52-"at- Itheir exteriors. As shown, the cutters- Dare-'carriedbetweenY the legsl 19l and 20 hereinabove referred to, on a common axiswhich extends horizontally 4between the 'arms 22 .and 23 'and y1101'-mal to the axes of the cuttersl C. It is preferred that the elements 5l)and 50 beof diierentlengths, .so that the element 50 covers the centerof the well bore and overlaps the path of the element 50 as the tooloperates. The teeth 52 and 52 are helically pitched in oppositedirections and are provided with staggered notches 53 and 53' so thatthe teeth of one cutter do not track in the path of the -teethof theother cutter.

The means provided forfrotatably carrying the cutters C involve atrunnion 55 for each element 30. The trunnions- 55 project upwardly andoutwardly from the outer sides 56-1ofy the-divergentlegs-19 and 20,respec` tively, and each trunnionhas aL radial bearing'surface 57 vrandan annular race 48-at the outer terminal end thereof. Each cutterelementhas a bore 59'thatis adapted to receive a trunnion 55- and whichhas an inner bearing surface 6l) -and an lannular racel 61 -at the-outerend thereof. An annular row or series of anti-friction4 rollers 62, orthellike,-gis'provided between the bearing surfaces 57 and 60, land therollers areretained by axially spaced shoulders inthe member 30;

The cutters C are retained on the trunnions 551by means of an annunlarseriesof balls 63 operatingV in the races 4S f and 61. As shown, therace @lis formed inthe bore59 to open radially inwardly while the raceSie formed in the trunnion 55to open longitudinally and radiallyoutwardly. in practice, a retainer`64 is threadedlyl secured to they endportionA ofthe trunnion 55at S5-and, as shown, forms the outer halfofthe race 4S. A suitable lock pin, or kthe like, may be provided tosecure the retainer in position. lt will be apparent how the balls 63lare inserted between the races and retained therein to take axial thrustthereby-rotatably securing the cutter on the trumn'on.. As Vshown inFig. 3 of the drawings,` a'cover plate 66 is provided and closes theouter end of the bore 59 covering the'bearing rollers 62'and`balls 63and the retainer 64; Welding,` or 'the like, isused to fasten the plate66 in place.

The means for rotatably carrying the cutters D involves a pin 7S andbearing supports for the pin. The pin 75 is a simple elongate part thatextends trans-y versely of the bottom of the body A ,between the .arms22 and 23. caring openings 75and 77`are provided inthe arms at-the sidesof the body A and a bearing opening 78 is providedn the web 21betweenthe ele-v ments 50 and 50'. As shown, in Fig. 4 of the drawings, the web21 is off-set relative to the central axis of the body A, and thebearing openings 76, 77 and 78'are aligned in the arms 22 and 23 .andweb 21 for receiving and carrying the pin 75. The pin 75 has anouterbearing surface 82, while the elements 50 and 50 have inner bearingsurfaces 83 and S3'. An annular row of rollers 84 is provided betweenthe bearing lsurfacesof each'cutter and the pin, so that the cutters arefree to rotate on the pin. The pin 75 may be suitably secured inthebearing openings in the arms and web of the body A by means of welding,or the like.

The flushing means provided by the present invention provides forcleaning. of both sets ofy rollers. That is, the flushing means acts. toflush or clean the bore gauging cutters Cjas well as the bottom vorcross sectional cutter D. As clearly illustrated in Figs. 3 and 4 of thedrawings, jets. are provided whichv direct ythe ow of mud from thedri11ing ,string.,to.the, edge;` 34 ofcach.v

cutter element 30. It will be noted that the streams of mud delivered bythe jets 90 are split by the edges 34, so that a portion of the mudcleans the end faces 38 of the cutters while a portion of the mud cleansthe periphery thereof. I ets 91 carry mud to the lower cross sectionalcutters D as shown in Fig. 4 of the drawings.

In operation of the bit, the shank or pin is connected with the lowerend of the drilling string and the bit is operated on the lower end ofthe string in the usual manner. As the bit i-s fed downwardly the crosssection cutters D act on and cut away the formation in the centralportion of the bottom 15 of the bore while the bore gauging cutters Cact on and cut away the formation at the outer portion of the bottom 15and cut the wall 14 of the bore to gauge. The cutters are positioned sothat they have direct active cutting engagement with the entire bottomof the well bore, as the tool or bit revolves, there being no outer legsor supports as employed in usual bit constructions. The circulation uidor mud is pumped downwardly through the drilling string and dischargesthrough the jets 90 and 91 to clear the chips from the cutters and fromthe bottom and sides of the well bore.

In order to build angle in a deected well bore as clearly illustrated inFig. 2 of the drawings, a substantial amount of weight is applied to thebit through the drill string as indicated by the arrow X. The drillstring is then rotated whereupon the cutters C act to cut upon the highside of the well bore as indicated by the arrow Z', there being no outerlegs or supports to prevent such action as is the case with ordinary bitconstructions.

In order to drop angle or to return a well bore to vertical, as clearlyillustrated in Fig. 1 of the drawings, it is merely necessary to useless weight of the drilling string in the direction indicated by thearrow X and to rotate the string so that the cutters C act upon thelower yside of the well bore as indicated by the arrow Z, there being nointerference from body parts such as legs or supports.

Having described only typical preferred tforms and applications of ourinvention, We do not Wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to ourselves anyvariations or modifications that may appear to those skilled in the artand fall within the scope of the following claims:

Having described our invention, we claim:

l. A well boring bit of the character referred to including, an elongatevertically disposed cylindrical body, a pair of downwardly divergentlegs depending from diametrically opposite sides of the body, a pair ofarms depending from diametrically opposing sides of the body and spaced90 from the legs, a pair of axially aligned elongate, horizontallydisposed roller cutters of different longitudinal extent extendingbetween and rotatably carried by the arms to occur between the lower endportions of the legs and engage the bottom of a well bore, asubstantially disc-shaped cutter with a substantially radially outwardlyfacing frusto-conical end rotatably carried by each leg to projectoutwardly therefrom on an axis disposed radially outwardly and upwardlyrelative to the central vertical axis of the body, each disc-shapedcutter having circumferentially spaced axially disposed cutting teethabout its outer periphery to engage the bottom of the well bore andhaving outwardly projecting radially disposed bore engaging teeth onsaid frusto-conical end to engage the bore, said bore engaging teethbeing in radial alignment with and joining the bottom engaging teethrelated thereto, said bore engaging teeth being spherically curved abouta common point occurring on the central vertical axis of the bit andushing means for each discshaped cutter including a uid handling bore inthe body and a jet opening in the body related to each of said cuttersand adapted to direct circulating uid on the cutters between the axiallyand radially disposed teeth thereon.

2. A well boring bit of the character referred to including, an elongatevertically disposed body, a pair of downwardly divergent legs dependingfrom diametrically opposite sides of the body, a pair of arms dependingfrom diametrically opposite sides of the body and spaced from the legs,a web extending between the legs and offset from the vertical axis ofthe body, an elongate horizontally disposed shaft extending between andcarried by the arms to intersect the vertical axis of the body, projectthrough the web and occur between the lower end portions of the legs, anelongate roller cutter rotatably carried by the shaft between the weband each arm and adapted to engage the bottom of a well bore, asubstantially disc-shaped cutter with a radially outwardly facingfrusto-conical end rotatably carried by each leg to project radiallyoutwardly therefrom on a radially outwardly and upwardly inclined axisand having circumferentially spaced axially disposed cutting teeth aboutits periphery to engage the bottom of the well bore and having outwardlyprojecting, radially disposed bore engaging teeth on said frusto-conicalend to engage the wall of the bore, said bore engaging teeth beingarranged in radial alignment with the axially disposed teeth andextending radially outwardly from said edge of the cutter to join withthe adjacent ends of the axially disposed teeth related thereto, saidradially disposed teeth being spherically curved about a common pointoccurring on the central vertical axis of the bit, and ushing means foreach cutter including a fluid handling bore in the body and jet openingsin the lower end of the body related to each cutter.

3. A well boring bit of the character referred to including, an elongatevertically disposed body, a pair of downwardly divergent legs dependingfrom diametrically opposite sides of the body, a pair of arms dependingfrom diametrically opposite sides of the body and4k spaced 90 from thelower end portion of the legs, a web extending between the legs andoffset from the vertical axis of the body, an elongate horizontallydisposed shaft extending between and carried by the arms to intersectthe vertical axis of the body, project through the web and occur betweenthe lower end portions of the legs, an elongate roller cutter rotatablycarried by the shaft between the web and each arm and adapted to engagethe bottom of a well bore, a substantially disc-shaped cutter with aradially outwardly facing frusto-conical end rotatably carried by eachleg to project radially outwardly therefrom on a radially outwardly andupwardly inclined axis and having axially disposed cutting teeth aboutits periphery to engage the bottom of the well bore and having outwardlyprojecting, radially disposed bore engaging teeth on said irusto-conicalend to engage the wall of the bore, said bore engaging teeth beingarranged in radial alignment with the axially disposed teeth andextending radially outwardly from said edge of the cutter to join withthe adjacent ends of the axially disposed teeth related thereto, saidradially disposed teeth being spherically curved about a common pointoccurring on the central vertical axis of the bit, and flushing meansfor each cutter including a uid handling bore in the body and jetopenings in the lower end of the body related to each cutter, said jetopenings related to the roller cutter being directed towards the top ofeach roller cutter at a point intermediate its ends, said jet openingrelated to each disc-shaped cutter being directed at the top of eachdisc-shaped cutter at a point where said frusto-conical end joins theouter periphery of the cutter.

References Cited in the le of this patent UNITED STATES PATENTS1,195,208 Griin Aug. 22, 1916 1,284,453 Reed Nov. 12, 1918 1,327,913Hughes Ian. 13, 1920 2,058,626 Reed Oct. 27, 1936 2,634,955 Johnson Apr.14, 1953

